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Test:=[x1,x2,x3];
for j from 1 to nops(Test) do
   dummy:=proc(i::nonnegint)   
   local k;
      if i=0 then return a0;
         elif i=1 then return a1;
         else return dummy(i-1)+dummy(i-2);
      end if;
   end proc:
   Test[j]:=dummy;
end do:

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Test:=[x1,x2];
n:=[2,3];
Var:=[a0,a1,b0,b1,b2];
k:=[1,1,1,0,1];

for j from 1 to nops(Test) do
  dummy:=proc(i::nonnegint)
     local x,y,Rek;
     for x from 0 to n[j]-1 do 
        if i=x then 
          return Var[x+1];
        end if;
      end do;
      Rek:=0;
      for y from 1 to n[j] do 
        Rek:=Rek +k[n[j]-y+1]*Hilf(i-y);
      end do;
      return Rek;
    end proc:
  Test[j]:=dummy;
end do: